the average wattage of the 138 pulse start is 272 to 298 watts, for the M58 it is 290 to 298 watts.

so a average wattage of 290 just says the ballast is 86% efficient and only 14% of the power used is given off in heat.

Steve

the scarey thing is, ... you know this stuff..
lol

Doug

:eek: hmmm... um ya that is kinda a scarry eh :confused: :mrgreen:

Steve

So we still have not answered the question "what is HQI" :question:

Ok HQI is one of the most commenlhy misused terms in the hobby but it is used so we will use it.. to answer your question I will defin the real HQI first.

Wattages Bulb Shape Base
70 T-6 Double Ended RSC
70 T-7.5 Single Ended G12
150 T-7 Double Ended RSC
150 T-7.5 Single Ended G12
250 T-9.5 Double Ended FC2
250 T-14.5 Single Ended E40Mogul
400 T-14.5 Single Ended E40Mogul

SYLVANIA HQI® metal halide lamps combine excellent
brightness, long life and high CRI in a compact package
for optimal lamp performance.
The HQI family of metal halide lamps is manufactured with
the addition of rare earth metal halides to improve color
rendering and luminous efficacy. With their compact size
and very short arc discharge length, these lamps come very
close to being a point source of light allowing luminaire
manufacturers to design highly efficient fixtures. The very
high color rendering, white light, compact size, long life and
high efficacy make these lamps ideal for replacing tungsten
halogen in certain retail applications.


so from all that garbage we get that it is a new manufacturing techneque using rare earth metal halide gasses and have a shorter arc length.

because of this they needed the amprage and voltage applied in a different mannor to strike the arch and maintain it properly. also the usage of the Cap on the hqi ballast is to regulate the voltage like an acumalator instad of like a flow restrictor which was a little confusing at first.

Steve

In the hobby any double ended bulb is called HQI which ina sence it is but so are most of the europen SE bulbs also as they are based ont he same design that Osram used, they just call it something else.

Steve

Thanks for the replies everyone.. seems the thread got a life of its own. :biggrin: Still unsure tho. sounds like the Electronic ballast isn't worth the extra $$ for the small energy savings? But then it sounds better cuz you can use any bulb? Am I right on that?

What about the Sun Aquatics Electronic ballasts.. when they finally become available... should be a decent deal shouldn't it?

Doug

Re: Electric vs Tar
 

[quote="StirCrazy"]Steve, sorry to beat a dead dog here, but, both electronic and pulse start ballasts use the same method of starting the bulb? But because we are using North American current we rely on the probe in the bulb to start the light? What does the ignitor do? Probe start bulbs don't use the remote ignitor, am I correct? So, is there any issues with using a probe start bulb with a pulse start ballast? I hope this isn't a stupid question, just trying to get things clear in my head.

Doug

probe start is for ballast with out starters, the ballast sends open current to the bulb and lets it go, if you have a pulse start, electric or HQI ballast they will not allow open current to the bulb so the probe cannot start the bulb. so in thoes cases you are relying on the starter of the ballast to start the arc in the bulb.

Steve